[saurik]

It does suck that the usual 64-bit calling convention limits the size of strict passed by value to 64-bits :/.

[gpderetta]

At least linux AMD64 ABI allows passing (and returning) 128 bit structures by registers, which is perfect for the ptr/len case.

[thysultan]

You could store two 32 bit fields and cast the second to a pointer when needed, and the first treat as a length.